Hello,
I recently purchased a D&D slip-on exhaust. I tried to research more about the exhaust, but there is no model # on the exhaust.
However, I found a video of another owner of a GS500F with the same exhaust:
https://www.youtube.com/watch?v=WGpDH2cT6Pg
In the video description the GS500F owner states he didn't need to rejet, but I think I need to do it in my situation.
It seems the bike runs super lean at the moment. I have stock air filter and air box in (I would like to keep these items stock if possible).
Problem: Rolling up to a stop light the bike will stall before I stop completely. Idle RPMS are below 1200 RPM sometimes even below 1000RPM.
I have no idea on how I should approach this rejet stage. I've read through many posts, threads, and even the wiki from gstwins.
I do not know what size of main and pilot jets I should purchase. I would ask the knowledgeable members and gurus on this forum to shed some of their knowledge and opinion on this matter.
Thank you! Your input is much appreciated! :D
The only symptoms are a low idle / stalling when you stop? If so, you don't need new main jets (at least, they won't solve your stalling problem). First, try turning your idle screw in so it idles around 1400 rpm. Then try setting your mixture screws to 2.5 or 3 turns out. You have the stock pilot jets, correct? You might have to go more turns out on the mixture screws or even larger pilots.
Once your idle circuit is dialed in, be sure to set the idle back to factory spec (I believe it's 1200 +/- 100 rpm).
Quote from: Big Rich on July 03, 2014, 11:22:57 PM
The only symptoms are a low idle / stalling when you stop? If so, you don't need new main jets (at least, they won't solve your stalling problem). First, try turning your idle screw in so it idles around 1400 rpm. Then try setting your mixture screws to 2.5 or 3 turns out. You have the stock pilot jets, correct? You might have to go more turns out on the mixture screws or even larger pilots.
Once your idle circuit is dialed in, be sure to set the idle back to factory spec (I believe it's 1200 +/- 100 rpm).
Thank you, Big Rich for your help.
Yes, I have low idle and stalling when coming to a complete stop.
I forgot to mention that there is some popping sounds coming from the exhaust when I decelerate. I believe there may be some popping sounds when I accelerate too.
The jets should be stock. The previous owner didn't rejet the bike when I asked him. I will double check tomorrow, and see if I can make the new adjustment to the pilot jet/idle screw.
I will report back asap!
hi iceman86, im from the uk and have recently been having similar problems trying to work out similar jetting for a can i plan to use, if your pilot jets are still the stock 17.5 i suggest fitting 20's, this stops the rpm dips you encounter,
have a read of the jetting wiki if you havnt already.
http://wiki.gstwins.com/index.php?n=Upgrades.Rejetting
"2001 - 2007 Carburetors
The advantage of these newer carbs are the inclusion of a Mid Main Jet that allows finer tuning of the fuel to air ratio of different throttle openings.
YEAR + Jet Size
2001+ Stock - 17.5 Pilots / 60 Mid Main / 127.5 Main
2004+ Stock - 17.5 Pilots / 60 Mid Main / 130.0 Main
These bikes use Mikuni Carburetors / Jets with the following part numbers for their jets:
Pilots = N224.103 or VM28/486 (apparently they are the same)
Mid Main & Main = N102.221
To what degree
A conservative Starting Point for upgraded Jetting (Pilots/Mid Main/Main) for a:
Stock GS500 = 20/60/135
Drop in K&N Air Filter Only = 20/62.5/140
K&N Pod or Lunchbox Air Filter Only = 20/65/142.5
Drop in K&N Air Filter + Sports Exhaust = 20/62.5/142.5
K&N Pod or Lunchbox Air Filter + Sports Exhaust = 20/65/145
Unfortunately Re-Jetting is a black art (so many variables including humidity, altitude, engine condition etc etc) so often much tweaking of jet sizes is needed to find the perfect combination.
See the Matrix for what other users have found to work.
Remember: The GS500 has two carburetors so you will require two of each jets!"
Ive sent a few messages back and forth with Buddha who's the main bloke for jetting advice and he suggested a 132.5 over a 135 main jet, so maby get the 20 pilot jets and 132.5 and 135 main jets as they are dirt cheap to buy.
That way you know your bikes definitely going to be fueling spot on, Buddha is even able to supply a comprehensive kit for your carbs including float bowl screws as the sock ones usually get mangled when you remove them, all you need to to is send him a message.
hope this clears eveerything up :)
If it drops to below the set idle rpm when you release the throttle and comes back to idle - you're rich.
If you are lean after fully warm, the bike will idle @ 3K or somewhere round that, if it idles 1200 or so when cold.
If it takes longer than 30 seconds in summer to where it will hold idle without choke - you're lean.
OTOH, if it will start without choke in summer - you're prolly a wee bit rich ... if it will do that in winter you're very rich.
Cool.
Buddha.
The above is for jetting @ idle or @ very small throttle opening only. You may be rich there but lean elsewhere ... and you can also be lean there but fine elsewhere.
Cool.
Buddha.
Hello,
Thanks for everyone help on this!
I am little confused and uncertain, but is this the mixture screw Big Rich is referring to?
Note: I have a GS500F 2005.
Quote from: Big Rich on July 03, 2014, 11:22:57 PM
The only symptoms are a low idle / stalling when you stop? If so, you don't need new main jets (at least, they won't solve your stalling problem). First, try turning your idle screw in so it idles around 1400 rpm. Then try setting your mixture screws to 2.5 or 3 turns out. You have the stock pilot jets, correct? You might have to go more turns out on the mixture screws or even larger pilots.
Once your idle circuit is dialed in, be sure to set the idle back to factory spec (I believe it's 1200 +/- 100 rpm).
(http://i205.photobucket.com/albums/bb17/ben_2_go/Motorcycle%20Stuff/Mikuni%20BST33SS%20Carbs/bottom2-1.jpg)
Taken from: http://gstwins.com/gsboard/index.php?topic=56601.0
Here are pictures of my carbs:
(http://i.imgur.com/tIy5hLvl.jpg) (http://imgur.com/tIy5hLv)
(http://i.imgur.com/DaBR1Pll.jpg) (http://imgur.com/DaBR1Pl)
Would anyone be kind enough to help me confirm and identify the location of my mixture screw? I am concern I may taper with the wrong screw :(
Yours are basically in the exact same position. And yours are all nice and shiny brass, not dull and corroded like the first pic.
Quote from: Big Rich on July 07, 2014, 04:24:54 PM
Yours are basically in the exact same position. And yours are all nice and shiny brass, not dull and corroded like the first pic.
Thank you very much for replying back and answering my question, Big Rich!
I will make the adjustment and go for a test ride. I will report back asap on how she runs with the new adjustment.
Thank you to everyone once again!
Hello,
I made some adjustments with the mixture screws. I did 4.5 turns.
I went for a quick ride after warming up the bike and the results are:
1) I haven't stalled yet upon coming to a completely stop.
2) The popping sounds still occurs when I am decelerating.
Correct me if I am wrong, but the mixture screw on the GS500F 2005 controls the amount of fuel that flows thru only right?
Since I did 4.5 turns on the mixture screw and I no longer stall when coming upon a complete stop. I am and should be running a little rich now?
If that case should I reduce the amount of fuel being intake? Possible down to 3 to 3.5 turns? I am idling steadily between 1300-1200 RPM I believe.
If you need 4 turns on your pilot screws, you probably need to go up a size on your pilot jets. I'd never go past 4 turns myself.
If it still lags when you blip the throttle, larger pilots would be my guess, if everything else being OK.
Hello again,
Just follow up with some updates:
1) I went for a quick ride. Warmed up the bike for about 35-45 seconds. Idles around 1200 RPM.
2) The first 2-3 few stop lights I stalled as I came to a complete stop. The RPMs were struggling to stay at 1200 RPM (it was hanging low 1100-1000 RPM). I had to adjustment the idle screw on the spot a few times.
*The only way to prevent the bike from stalling as I come to a complete stop is to give a little gas so the RPM hovers above 1200 RPM.I stopped at a nearby friend's house for 20 minutes, and then I continue to ride to a nearby coffee shop.
1) Upon starting up the bike the idle speed was hanging steadily at 1500 RPM. I couldn't bring it below that with the idle adjustment screw.
2) As I rode home coming to a complete stop the bike didn't stall, and was steadily hanging at 1200-1100 RPM.
Am I not giving enough time for the bike to warm itself up?
Below is a video I made before I went home to showcase the popping sounds as the RPM descents:
https://vid.me/OmA
Would simply up-sizing only the pilot jets help resolves the 1) stalling issue and 2) popping sound from exhaust? I am uncertain on how to proceed at this point :(
Quote from: ace50 on July 08, 2014, 05:46:48 AM
If you need 4 turns on your pilot screws, you probably need to go up a size on your pilot jets. I'd never go past 4 turns myself.
If it still lags when you blip the throttle, larger pilots would be my guess, if everything else being OK.
The popping from the exhaust isn't THAT big of a problem. There's a very good chance your stock exhaust popped a little bit, but the quieter muffler hid it.
Try putting in a larger pilot, and then fine tune with the mixture screws. You may be left with slight popping on decel, you might not.
Quote from: Big Rich on July 08, 2014, 07:16:53 PM
The popping from the exhaust isn't THAT big of a problem. There's a very good chance your stock exhaust popped a little bit, but the quieter muffler hid it.
Try putting in a larger pilot, and then fine tune with the mixture screws. You may be left with slight popping on decel, you might not.
Thanks, Big Rich and everyone else :)
I guess I will try to get a pair of pilot jets @ 20 and main jets @ 135. I think much places online requires you purchase four jets at a time.
I will report back as soon as I get them installed and tuned. I am just concerned about the stalling at red lights. Could be dangerous :(
Quickly scanned thread, didn't see you mention if you have checked or know where your valves are set at.
Hanging rpms (bad idle) can just be your exhaust valves are too tight.
Quote from: ace50 on July 09, 2014, 05:53:21 AM
Quickly scanned thread, didn't see you mention if you have checked or know where your valves are set at.
Hanging rpms (bad idle) can just be your exhaust valves are too tight.
Hello ace50,
No, I do not know what are my valves are set at.
Is this the correct video to follow to inspect the valves?
https://www.youtube.com/watch?v=j4vRm9xADa8
That'll work!
Hello!
I just check my valve clearance and here are the results:
Left Exhaust
Current Shim Size: 2.62mm
Clearance: I was not able to determine the clearance as my smallest feeler gauge size at 0.02mm would not fit.
Right Exhaust
Currect Shim Size: 2.67mm
Clearance: 0.04mm
New Shim Size should be:
0.10-0.04= 0.06 ----- 2.67mm-0.06=2.61 (2.60mm)
*I got the 0.10 clearance from referring to this video by BaltimoreGS:
https://www.youtube.com/watch?v=5J19aNdXV08#t=630
Left Intake
Current Shim Size: 2.71mm
Clearance: I was not able to determine the clearance as my smallest feeler gauge size at 0.02mm would not fit.
Right Intake (In Spec)
Current Shim Size: 2.62mm
Clearance: 0.08mm
How do I determine what shim size I need to replace the Left Exhaust and Left Intake?
Should I follow this guide: http://gstwin.com/adjust_valves.htm and replace it with 0.05 thinner shim?
So the new Left Exhaust Shim Size would be: 2.62-0.05=2.57mm (2.50mm) and Left Intake Shim Size would be: 2.71-0.05=2.66mm (2.60mm)?
Also just to clarify should the camshaft notches be facing outwards when I am done? And not facing towards each other?
Thank you!
Try swapping the left and right intake shims since you couldn't get a measurement with the 2.70 shim. You'll find out if you need a 2.60 or a 2.65 shim that way. Just remember not to turn the camshafts with no shims under them.....
Quote from: Big Rich on July 09, 2014, 06:42:12 PM
Try swapping the left and right intake shims since you couldn't get a measurement with the 2.70 shim. You'll find out if you need a 2.60 or a 2.65 shim that way. Just remember not to turn the camshafts with no shims under them.....
Excellent idea, Big Rich! I just did that and here are the results
Left Intake
Current Shim Size: 2.62mm (Swap from Right Intake)
Clearance: 0.10
New Shim Size should be: 2.62+0.08=
2.70mm? :dunno_black:
I guess I can't check the Left Exhaust clearance without an extra shim in hand :(
Do you guys think my calculations is correct for the three new shims?
I set intakes (actually leave them) at the .03-.08 mm Suzuki spec and now set exhausts at my wider .08-.13 mm spec. My valve log for 180k miles on 2 GSs:
http://img.photobucket.com/albums/v443/jcp8832/GSvalvelogs_zps9ef7236a.jpg
If the 262 shim gives your left intake .10 mm clearance leave it and put the 262 from the left exhaust in the right intake.
Before you remove the 262 from the left exhaust check to see if you can rotate the bucket/shim with your finger with the cam lobe turned away from the shim, if you can a 250 should bring it into the new wider spec range. A new 260 should fix the right exhaust.
REF:
http://img.photobucket.com/albums/v443/jcp8832/gs500signalgenerators_zps2134172a.jpg
Quote from: gsJack on July 09, 2014, 09:39:18 PM
I set intakes (actually leave them) at the .03-.08 mm Suzuki spec and now set exhausts at my wider .08-.13 mm spec. My valve log for 180k miles on 2 GSs:
http://img.photobucket.com/albums/v443/jcp8832/GSvalvelogs_zps9ef7236a.jpg
If the 262 shim gives your left intake .10 mm clearance leave it and put the 262 from the left exhaust in the right intake.
Before you remove the 262 from the left exhaust check to see if you can rotate the bucket/shim with your finger with the cam lobe turned away from the shim, if you can a 250 should bring it into the new wider spec range. A new 260 should fix the right exhaust.
REF:
http://img.photobucket.com/albums/v443/jcp8832/gs500signalgenerators_zps2134172a.jpg
Thank you very much for your advice, gsJack!
I didn't think about swapping the Left Exhaust Shim to Right Intake! Great idea!
I was able to rotate the shims and buckets on Left/Right Intake and Right Exhaust.
I wasn't able to rotate the bucket on Left Exhaust, but I think I was able to rotate the shim around though.
I will try again tomorrow to double check everything.
I don't know what to do if I can't slide a feeler gauge or rotate the shim bucket on the Left Exhaust...!
You mentioned last post you had a tight bucket on the left exhaust and was going to check it again in the morning, I assume it's still tight? If so try checking for compression in that cylinder with the 262 shim in it. If you have cold compression you'll probably be OK with putting in a 250 shim, at least you'll be able to get a reading on it. With the shim out and cam lobe away see if you can turn the bucket, if so then it's just a tight valve and you'll probably need a even smaller shim.
Quote from: gsJack on July 11, 2014, 09:14:32 PM
You mentioned last post you had a tight bucket on the left exhaust and was going to check it again in the morning, I assume it's still tight? If so try checking for compression in that cylinder with the 262 shim in it. If you have cold compression you'll probably be OK with putting in a 250 shim, at least you'll be able to get a reading on it. With the shim out and cam lobe away see if you can turn the bucket, if so then it's just a tight valve and you'll probably need a even smaller shim.
Yeah, I tried again checking all the shims the next day and the results are the same. I ordered an extra 2.50 and 2.55 shim in case, and hopefully they will fit and give me the necessary clearance I need. Or get find out what is the actually clearance. Good tip on rotating the bucket. I actually didn't think about that :(
I also decided to upgrade the air box to a k&n air filter, and I ordered 20/65/145 jets along with it. There is a slight improvement as well when I turn down the mixture screws to 3.5 turns, but the bike still doesn't feel the same stable yet.
I hope the following week I can fine tune the bike to be more stable. Didn't think installing a slip-on would affect the bike's functionality that significantly :(
I am very thankful for everyone's assistance and knowledge on this! I will keep the updates coming :)
Look at it this way: the slip on exhaust made you question your bikes performance, and now you know your valves were out of spec. Don't really want to ignore those valves.....
Quote from: Big Rich on July 11, 2014, 11:57:17 PM
Look at it this way: the slip on exhaust made you question your bikes performance, and now you know your valves were out of spec. Don't really want to ignore those valves.....
True! Very true! I am actually glad I did the valve clearance check. It's been a fun, stressful learning experience for me.
It's just the rejetting that concerns me the most, because I understand its like a black art. Just have to keep fine tuning it to get the perfect combo.
Also the exhaust is so much louder now... lol! I'm worry I am distributing my neighbors when I warm her up. I might have to find a way to make a DIY baffle for it.
Hello everyone! And thank you to everyone who help me out with this dilemma so far. Much appreciated.
The shims arrived today! I went straight to the bike to install them.
Valve Clearance Before:
Left Exhaust | | Right Exhaust | | Left Intake | | Right Intake |
Shim Size: | 2.62 | Shim Size: | 2.67 | Shim Size: | 2.62 | Shim Size: | 2.62 |
Clearance: | N/A | Clearance: | 0.04 | Clearance: | 0.10 | Clearance: | 0.08 |
New Shim: | N/A | New Shim: | 2.61 | New Shim: | 2.64 | New Shim: | None |
New Valve Clearance:
Left Exhaust | | Right Exhaust | | Left Intake | | Right Intake |
Shim Size: | 2.50 | Shim Size: | 2.60 | Shim Size: | 2.62 | Shim Size: | 2.62 |
Clearance: | 0.07 | Clearance: | 0.07 | Clearance: | 0.05 | Clearance: | 0.08 |
I believe this resolves the valve clearance adjustments! I made sure to face down the shims so next time I check or someone else they can actually read the shim.
Thank you for everyone's help once again!
Now I am just waiting for those mikuni pilot/main jets to arrive. It was rather extremely difficult to find a place that would ship to Canada without $25+ shipping :(
Buddha ships to canadia, India and china ... only charges $5 more for shipping.
Anyway 145 with K&N and slip on may be lean. With 65, you should be good with 20/147.5. On the screws 3.5 turns is OK. You need to worry after 5 turns ...
Cool.
Buddha.
Quote from: The Buddha on July 18, 2014, 06:50:20 PM
Buddha ships to canadia, India and china ... only charges $5 more for shipping.
Anyway 145 with K&N and slip on may be lean. With 65, you should be good with 20/147.5. On the screws 3.5 turns is OK. You need to worry after 5 turns ...
Cool.
Buddha.
Hello Buddha!
Thanks for the suggestions and the offer!
Someone mentioned to me you sell a kit... I should've PM you instead about those jets.
If I do end up needing a 147.5 jets would you be able to sell me a pair? What else do you sell for GS500 E/F? For future reference :)
Hello,
I've done a few changes and tune up to the bike.
Installed K&N Lunchbox with Yoshi TRS exhaust now.
Jets used are 20/65/145 (Pilots/Mid Main/Main) - 3.5 Turns.
I am experiencing some high idle and a weird sound at idle (sounds like the bike is farting somewhere).
I have a video recording of the sound, and was wondering if anyone know what is causing this sound?
https://vid.me/sSx
Quote from: iceman86 on September 08, 2014, 06:08:29 PM
Hello,
I've done a few changes and tune up to the bike.
Installed K&N Lunchbox with Yoshi TRS exhaust now.
Jets used are 20/65/145 (Pilots/Mid Main/Main) - 3.5 Turns.
I am experiencing some high idle and a weird sound at idle (sounds like the bike is farting somewhere).
I have a video recording of the sound, and was wondering if anyone know what is causing this sound?
https://vid.me/sSx
I have Yosh TRS too on a 96 with 02 carbs but with airbox and stock filter.
High idle - make sure you dont have any air leaks or exhaust leavs etc etc, and give the air screws another 1/2 turn (how much is it hanging)
farting elsewhere - exactly where and under what circumstances ... details.
Cool.
buddha.
Hello,
I started up the bike just now to identify the farting sound.
The sound is coming out of this tube right here:
(http://i.imgur.com/q3l7Wbkl.jpg) (http://imgur.com/q3l7Wbk)
(The long tube hanging out on the side of the bike.)
(http://i.imgur.com/LhjLJ0al.jpg) (http://imgur.com/LhjLJ0a)
(The tube hanging off screen on the bottom left - seems to be connected to the front of the carbs intake slot area).
------
Update:
After some closer observation I believe the hose is the vacuum hose that should be connected to the petcock.
Video Reference: https://www.youtube.com/watch?v=AJh1hxNf7BA#t=1013
After I slide the hose back in place to the petcock I notice the sound was still occurring, and this time it was the left side of the K&N Lunchbox making the sound.
I realize this hose was sucking air in. I put my thumb over it and the bike steadily climb up in rpms leading to high idle.
I have no idea what is causing this farting sound to occur :(
Dude I am nearly sure that tube gotta be plugged up or connected to some ridiculously complicated and in accessible charcoal cannister ...
Put your finger over it and check for vacuum. If the farting stops, well you've found the Butthole of your bike. Plug it and you'll be OK.
Cool.
Buddha.
Ok! I finally sorted out the hose issue I had.
1) The hose I mention above was indeed a vacuum hose that is suppose to be connected to the backside of the petcock (refer to this video (http://www.youtube.com/watch?v=AJh1hxNf7BA#t=1013))
*It wasn't the charcoal canister, Buddha! I checked and notice a hose was already connected in there :).
2) The below hose was also not connected on the left carbs. I plugged it back in.
(http://i.imgur.com/41KzkHdl.jpg)
(Image taken from Vertigo from this post/thread (http://gstwins.com/gsboard/index.php?topic=52921.0), thank you! Just using it as reference)
I went for a 20mins ride around to test out the bike. The results for the time being is the following:
1) Start/Warm Up are quicker now (have not experience high idle yet).
2) Throttle is a lot more responsive
3) Exhaust is roaring like a beast when I want it to!
4) No farting sounds, but still a few pops coming from exhaust on hard acceleration I think.
Thanks for everyone's help! Particularly the great Buddha of course! I'll keep yall posted if anything changes :)
Quote from: The Buddha on July 04, 2014, 07:40:01 PM
If it drops to below the set idle rpm when you release the throttle and comes back to idle - you're rich.
If you are lean after fully warm, the bike will idle @ 3K or somewhere round that, if it idles 1200 or so when cold.
If it takes longer than 30 seconds in summer to where it will hold idle without choke - you're lean.
OTOH, if it will start without choke in summer - you're prolly a wee bit rich ... if it will do that in winter you're very rich.
Cool.
Buddha.
I'm having hanging idle at 3K after warm up and backfire in carbs, valves are fine. I shortened my stock exhaust nearly two years ago and problems since than. thanks for this tip, I guess I need rejet too :bowdown:
hanging idle means the idle is set too fast. Most likely cause of that is you set the idle mixture before the bike was fully warmed up, or there is some other cause of low idle like vacuum leaks. Reset the idle mixture after you have ridden 20 minutes on the road (not on center stand), and then set the idle as low as it will idle, don't necessarily try to aim for 1200 rpm. Then if you have hanging idle after it's very warm (long ride), lower the idle speed a tiny bit at a time until it goes away, or likewise if you have idle droop (drops below the specified idle speed and then returns) then raise the idle speed a touch. Takes a bit of tuning with your right hand while at stop lights to get it truly dialed in perfectly, but the key is to not make any idle adjustments until it's completely and fully warmed up.
It will likely run very poorly when taken completely off choke until it has been running like 5 minutes, so don't assume something's wrong if you try to take it off choke after 30 seconds and it stalls at idle.